Monsanto's GM patents make it illegal for farmers to replant the seed from the former year's crop (a practice down for thousands of years) on the grounds of patent infringement. What this also means is that if a non-GMO crop is somehow altered, naturally, by the Monsanto GMO crops, Monsanto now owns the rights to those seeds as well - making them unplantable the next year.

These practices and more make Monsanto a shady corporation worthy of avoiding.